• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.62-70
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• 2011

The antibacterial effects of nine lactic acid bacteria (LAB) against Campylobacter jejuni were investigated by using agar gel diffusion and co-culture assays. Some differences were recorded between the inhibition effects measured with these two methods. Only two LAB, Lb. pentosus CWBI B78 and E. faecium THT, exhibited a clear anti- Campylobacter activity in co-culture assay with dehydrated poultry excreta mixed with ground straw (DPE/GS) as the only growth substrate source. It was observed that the supplementation of such medium with a cellulase A complex (Beldem S.A.) enhanced the antimicrobial effect of both LAB strains. The co-culture medium acidification and the C. jejuni were positively correlated with the cellulase A concentration. The antibacterial effect was characterized by the lactic acid production from the homofermentative E. faecium THT and the lactic and acetic acids production from the heterofermentative Lb. pentosus CWBI B78. The antagonistic properties of LAB strains and enzyme combination could be used in strategies aiming at the reduction of Campylobacter prevalence in the poultry production chain and consequently the risk of human infection.

• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.37-42
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• 2011

A new versatile acrylonitrile-bioconverting strain isolated from a petroleum-contaminated sludge sample and identified as Rhodococcus ruber AKSH-84 was used for optimization of medium and biotransformation conditions for nitrilase activity to produce acrylic acid. A simple and rapid HPLC protocol was optimized for quantification of acrylic acid, acrylamide, and acrylonitrile. The optimal medium conditions for nitrilase activity were pH of 7.0, temperature of $30^{\circ}C$, agitation of 150 rpm, and inoculum level of 2%. Glycerol as a carbon source and sodium nitrate as the nitrogen source provided good nutritional sources for achieving good biotransformation. Nitrilase activity was constitutive in nature and was in the exponential growth phase after 24 h of incubation under optimal conditions without addition of any inducer. The substrate preference was acrylonitrile and acetonitrile. The present work demonstrates the biotransformation of acrylonitrile to acrylic acid with the new strain, R. ruber AKSH-84, which can be used in green biosynthesis of acrylic acid for biotechnological processes. The nitrilase produced by the isolate was purified and characterized.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.207-210
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• 2000

Pseudomonas oleovorans was cultivated to produce medium chain length polyhydroxyalkanoates (MCL-PHA) fram octanoic acid and ammonium nitrate as carbon and nitrogen source, respectively, by a pH-stat fed-batch culture technique. The octanoate concentration of the culture broth was maintained below 4 g/L by feeding the mixture of octanoic acid and ammonium nitrate when the culture pH rose above high limit. The effect of the ratio of octanoic acid to ammonium nitrate (C/N ratio) in the feed on the PHA production was examined. The final cell concentrations of 62.5, 54.7, and 9.5 g/L, PHA contents of 62.9, 75.1, and 67.6% of dry cell weight, and productivities of 1.03, 0.632, and 0.161 g/L/h were obtained when the C/N ratio in the feed were 10, 20, and 100 g octanoic acid/g ammonium nitrate, respectively.

• KSBB Journal
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• v.17 no.3
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• pp.271-275
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• 2002

Fatty Acid contents of entomopathogenic nematodes(EPNs) were examined by various types of nematodes and culture methods. Seven different types EPNs cultured by in vivo did not contain same fatty acid contents, but similar compositions. It was also found that Steinernema carpocapsae among EPNs cultured by in vivo and in vitro contained not only different fatty acid contents, but also revealed distinctive motilities in a soil. The addition of olive oil in the in vitro culture medium resulted in similar fatty acid contents of S. carpocapsae to in vivo and greatly improved the pathogenicity of nematodes compared to that of soy oil in the medium.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.294-301
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• 2001

The effects of including glycine and isonicotinic acid hydrazide (INH) in the growth medium (Luria broth, LBG) on the subsequent lysozyme-imduced protoplast formation and transformation efficiency of Corynebacterium glutamicum were studied. The transformation efficiency of C. glutamicum AS019 increased up to 100-fold as the ocncentrationof glycine in the media increased from 0% to 5% (w/v), relative to cells grown in the absence of glycine. The presence of 5 mg/ml INH in the growth medium led to a further 10-fold increase in transformation efficiency. In addition, this transformation protocol was successfully applied to other strains of C. glutamicum. Both chemicals affected the mycolic acid attachment to the cell surface of C. glutamicum, when INH, the relative percentage of fatty acids of AS019 to the total lipids (mycolic acid plus fatty acids) decreased from 76.9% (in LBG) to 72.9% (in LBG-2% glycine) and 66.4% (in LBG-8 mg InG/ml), thereby suggeting that these chemicals also inhibit fatty acid synthesis.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.3
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• pp.344-348
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• 2006

This study was carried out to survey the effect of medicinal herbs on the growth of 3 strains of lactic starter cultures in MRS broth by the addition of 0, 1, 3, 5, and 10% water extract, after 30 hrs incubation. The pH, titratable acidity and O.D. of lactic acid bacteria were investigated to obtain fundamental knowledge for the development a new product. The effects of medicinal herbs extracts on the growth of lactic acid bacteria were variable depending upon the species of lactic acid bacteria and medicinal herbs extract. Growth of Str. thermohilus was activated by addition of 1 and 3% Angelica gigas water extract, but the basal medium plus 5 and 10% extract and growth of L. acidophilus and Bif. longum were depressed by the addition of extract. The pH and acid production ability dropped slightly in the basal medium plus 1 and 3% of extract. The other samples following the same trend as the control.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.37-40
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• 1996

Kinchi is and important source of various vitamins, minerals, dietary fiber, organic acids and other nutrients. In order to get a basic information for developing vitamins-rich funtional kimchi, we investigated microorganisms which are capable of synthesis of vitamin C in Kimchi system. Microorganisms isolated from aliquots of kimchi were screened and cultured by using MRS or nutrient agar medium. L-Ascorbic acid produced by microorganism in medium was measured with high performance liquid chromatography. As the result, we isolated two bacteria strins N7 and N5202 preducing L-ascorbic acid from the kimchi system. Morphological and Gram staining experiment showed that N7 was Gram positive bacilli, while N5202 was Gram negative. There were also several bacteria that were considered to synthesizs erythorbic acid which is an analog of ascorbic acid. These results suggested that vitamin C-rich functional food could be developed by using the kimchi microorganisms.

• Applied Biological Chemistry
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• v.17 no.2
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• pp.93-116
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• 1974

A potent intracellular-lipid-producing yeast, Rhodotorula glutinis var. glutinis SW-17, was screened out from a variety of arable soils, compost heaps, and fodders, and two strains of excellent extracellular-lipid-producing yeasts, Rhodotorula glutinis var. glutinis SW-5 and Rhodotorula graminis SW-54, were screened out from the surface of many species of leaves. And then the intra- and extra-cellular lipid productions by those Rhodotorula yeasts were studied. The results were as follows: 1. During the shaking culture of 8 days at $24^{\circ}C$, both the intra- and extra-cellular lipid accumulation started almost at the stationary phase of growth, when the nitrogen source in the medium was a little more than half used up. The intracellular lipid production by Rhodotorula glutinis var. glutinis SW-17 reached 58.42% (w/w) of dried yeast, and the extracellular lipid production by Rhodotorula graminis SW-54 amounted to 2.62g per liter of the medium. 2. After the carbon and nitrogen sources in the medium were almost consumed, if the yeasts were shake-cultured further in a state of starvation, the yeast cells re-utilized the already produced intra- and extra-cellular lipids and the lipids completely disappeared in the medium in about 90 days. 3. The relative concentration of carbon and nitrogen sources in the media greatly influenced both the intra- and extra-cellular lipid production. When the nitrogen source in the medium was almost used up for the growth of yeast, and excess carbon sources were still available, the lipid production vigorously proceeded. As long as the nitrogen source concentration in the medium was high, the lipid production was greatly suppressed. 4. The optimum pH for both the intra- and extra-cellular lipid production by those yeasts was pH 5.0-6.0. 5. The fatty acid components of the intracellular lipid of Rhodotorula glutinis var. glutinis SW-17 were myristic, palmitic, palmitoleic, stearic, oleic, linoleic, and linolenic acids. The largest components of the fatty acids were palmitic acid equivalent to 30-45% of the whole fatty acids and oleic acid equivalent to 35-50%. 6. The fatty acid components of the extracellular lipid of Rhodotorula glutinis var. glutinis SW-5 and Rhodotorula graminis SW-54 were myristic, palmitic, stearic, oleic, linoleic, linolenic, 3-D-hydroxypalmitic, and 3-D-hydroxystearic acids. The largest components of the fatty acids were 3-D-hydroxypalmitic acid equivalent to 22-25% of the acids and 3-D-hydroxystearic acid equivalent to 13-17%. 7. The polyol component of the intracellular lipids was only glycerol, whereas the polyols of extracellular lipids were glycerol, mannitol, xylitol and arabitol.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.328-333
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• 2000

The spore of Aspergillus niger KCTC-6144 was immobilized on alginate gel beads. When pumpkin powder was used with glucose for a medium of citric acid fermentation by Aspergillus niger beads, the beaded Aspergilus niger grew up inside the bead and mycelia penetrated through the pore of the bead membrane. The bead size became largely from 2.0∼2.5mm to 6∼8mm after growing at 30$\^{C}$ for 4 days. Studies of optimum culture conditions on citric acid fermentation using Aspergillus niger beads on pumpkin medium (pumpkin powder 1% +glucose 7%, pH 6.0) were carried out in submerged cultures on 250m1 Erlenmeyer flask. As a result, it was found that to reinforce 12% as carbon source was good for citric acid production and that 1% pumpkin powder was good as nitrogen and mineral source in orbital shaker (150rpm) at 30$\^{C}$ for 5 days. The optimum initial pH on citric acid production was pH 6.0 and it was found that 100 beads of immobilized Aspergillus niger was adequate for citric acid production in a 250ml Erlenmeyer flask containing 50m3 of pumpkin medium solution with orbital shaker at 30$\^{C}$ for 5 days. We also found that maximal production of citric acid was 23.5g/ℓ at optimal condition (at 30$\^{C}$ for 5 days, pH 6.0, and 100 beads and medium containing 1% pumpkin powder plus 12% glucose).

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1205-1215
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• 2017

In this study, the hydrolysis rate of palm kernel oil (HPKO) and shea butter were compared by in vitro digestion to develop low-digestible fats. HPKO exhibited a higher hydrolysis rate than shea butter. The initial rate and ${\Phi}max$ value of HPKO were 0.315 mM/s and 78.0%, while the corresponding values for shea butter were 0.117 mM/s and 41.4%. When the two fats were blended at various ratios, the hydrolysis rate, in terms of the ${\Phi}max$ value, was similar to that of shea butter until 2:8 (HPKO : shea butter, w/w). After the analysis of triacylglycerol species and the positional fatty acid composition, the factors that affected the hydrolysis rate were determined. The results suggest that the low hydrolysis rate of shea butter would be due mostly to the stearic acid located at the sn-1,3 positions of triacylglycerol molecules. These properties of shea butter are expected to be the nutritional benefits as a low-digestible fat in foods.